1. Field of the Invention 
The present invention relates to a computer hinge, and more particularly to a computer hinge which is able to not only facilitate the separation between the screen and the main frame of a laptop computer, but also provide a stop to the screen after the screen is separated from the main frame. 
2. Description of Related Art 
With reference to FIG. 6, a conventional computer hinge is composed of a male part (50) and a female part (60). The male part (50) has a first stem (51) and an extension (52) integrally formed with the first stem (51). The female part (60) has a hollow cylindrical portion (61) formed to correspond to the extension (52) and a second stem (62) integrally formed with the hollow cylindrical portion (61). 
When the pivot hinge of this kind is to be assembled, the extension (52) is interference fitted in the hollow cylindrical portion (61). Thereafter, with the first stem (51) and the second stem (62), the hinge is adapted to securely connect to surfaces of two elements of a device respectively, such as the screen and the main frame of a laptop computer. When the conventional computer hinge is in operation, the force required to maintain the screen at any desired angle is from the friction between the extension (52) and an interior face of the hollow cylindrical portion (61). Because this type of computer hinge provides only friction while in operation, the manufacturer still has to provide devices to facilitate the separation between the screen and the main frame and to stop the screen when the screen reaches a predetermined angle relative to the main frame. Mounting other devices to the computer hinge to respectively provide a separation force  between the screen and the main frame and a stopping force to the screen increase overall cost and the complexity of the hinge, which is something every manufacturer tries to avoid. 
To overcome the shortcomings, the present invention tends to provide an improved computer hinge to mitigate and obviate the aforementioned problems. 